The use of hyaluronic acid in the treatment of ankle osteoarthritis: a review of the evidence.

Ankle osteoarthritis (OA) is a progressive degenerative joint disease that causes ankle pain and functional limitation especially during walking. It tends to involve younger people with high functional request and has often a post-traumatic origin. Symptoms control through conservative treatment is essential to procrastinate as long as possible the need for surgery. Although few data are present in literature about the use of local viscosupplementation in ankle OA, their potential use for ankle OA has been suggested. We systematically reviewed literature to evaluate the best evidence about short and long term effectiveness of intra-articular HA injections in the treatment of ankle OA. After having screened titles and abstracts from PubMed, Ovid, Cochrane Reviews, Google Scholar, we identified 14 full text articles and collected the outcome rates of intra-articular cycles of HA injections in patients with symptomatic ankle OA. Only 4 randomized control trials were included. Ankle Osteoarthritis Scales (AOS), American Orthopedic Foot, Ankle Society (AOFAS) clinical rating score, visual analog scales (VAS), Western Ontario and McMaster Universities (WOMAC) OA Index of Pain, Stiffness, and Physical Function Score were most frequently used to evaluate outcomes. Although randomized trials showed scores improvement also in placebo-treated patients, current evidence suggests that viscosupplementation for treatment of ankle OA is a safe and effective method. More randomized controlled trials with a large number of patients that compare not only the different types, dosages and frequency of HA injections, but also the effectiveness of HA versus corticosteroids infiltrations and HA versus other types of conservative treatment are still needed.